Developer tools

35 fast, private utilities for the things developers paste around every day. Everything runs client-side, so tokens, keys and payloads never leave your browser.

Format & beautify

JSON Formatter & ValidatorPretty-print, validate and minify JSON with exact error positions.
SQL FormatterBeautify messy SQL queries with dialect-aware indentation.
XML Formatter & ValidatorPretty-print, validate and minify XML with error locations.
HTML Formatter & MinifierBeautify messy HTML or minify it, with inline CSS and JS formatted too.
CSS Formatter & MinifierBeautify CSS with one rule per line, or minify it for production.
JavaScript FormatterBeautify minified or messy JavaScript and JSON-like code.
Markdown Preview & to HTMLWrite Markdown with a live preview and export clean HTML.

Encode & decode

Base64 Encode & DecodeConvert text to Base64 and back, with full UTF-8 and URL-safe support.
URL Encoder & DecoderPercent-encode or decode URLs and query string values.
HTML Entity Encoder & DecoderEscape <, >, & and quotes for HTML, or decode entities to text.
JSON String Escape & UnescapeEscape text for a JSON string, or unescape \n, \" and \u sequences.
Number Base ConverterConvert between binary, octal, decimal and hexadecimal, any size.
URL Parser & Query String EditorSplit a URL into parts and edit its query parameters.

Tokens, hashes & security

JWT DecoderDecode a JSON Web Token’s header and payload and check its expiry.
JWT Encoder (HS256 Signer)Create and sign JSON Web Tokens with HS256, HS384 or HS512.
Hash Generator (MD5, SHA-256)MD5, SHA-1, SHA-256, SHA-384 and SHA-512 for text or files.
HMAC GeneratorCompute HMAC-SHA256, SHA-1, SHA-384 or SHA-512 signatures in hex or Base64.
Password GeneratorCreate strong random passwords or passphrases with a strength meter.
UUID GeneratorGenerate random UUID v4 or time-ordered v7 identifiers in bulk.

Convert data

CSV ⇄ JSON ConverterTurn CSV into JSON arrays or JSON back into CSV, with proper quoting.
JSON ⇄ YAML ConverterConvert JSON to YAML and YAML to JSON for configs and manifests.
XML to JSON ConverterConvert XML to JSON and JSON back to XML, with attributes kept.
JSON to TypeScriptGenerate TypeScript interfaces from a sample JSON object.
HTML to Markdown ConverterTurn HTML or rich text into clean Markdown.
Markdown Table GeneratorBuild Markdown tables from a grid or pasted spreadsheet cells.

Test, time & reference

Regex TesterTest JavaScript regular expressions with live highlighting and groups.
Unix Timestamp ConverterConvert epoch seconds or milliseconds to dates, and dates to epoch.
Cron Expression ParserExplain a cron schedule in plain English and list the next run times.
HTTP Status CodesSearchable list of HTTP status codes with plain-English meanings.
Chmod CalculatorConvert Linux file permissions between rwx checkboxes, octal and symbolic.
IP Subnet CalculatorCIDR to netmask, network, broadcast, host range and host count (IPv4).

Color & web design

Color Converter (HEX, RGB, HSL)Convert colors between HEX, RGB and HSL and check text contrast.
Color Contrast CheckerCheck WCAG 2.2 AA and AAA contrast ratios for text and UI colors.
CSS Gradient GeneratorDesign linear and radial CSS gradients visually and copy the code.
QR Code GeneratorMake QR codes for links, text or Wi-Fi and download PNG or SVG.

Why use browser-based developer tools?

Many popular online formatters and decoders send what you paste to a server. That is a real risk when the input is a production JWT, an API response with customer data, or a secret used to sign webhooks. Every developer tool on SB Tools is plain JavaScript running on this page — there is no backend that receives your input, which you can confirm in your browser’s network tab.

Tools are built on well-known open-source libraries where it matters (for example sql-formatter, js-beautify and js-yaml) and on the browser’s own Web Crypto API for SHA hashing, HMAC signing and secure random numbers.

Frequently asked questions

Is it safe to paste a JWT or API key here?

Yes. Decoding, signing and hashing happen in your browser with JavaScript and the Web Crypto API; nothing you paste is sent to SB Tools or anyone else.

Do these tools work offline?

Once a page has loaded, most developer tools keep working without a connection, because all of their code is already in your browser.

Which tool should I use to read a JWT?

Use the JWT Decoder to read the header and claims and check expiry, or the JWT Encoder to create and sign a test token with HS256, HS384 or HS512.